As concerns about ventilator acquired pneumonia (VAP) continue to mount in the practice of medicine, particularly in the developed world, attention has been focused on ways to reduce the frequency and severity of this potentially fatal condition. It has been found that one source of bacterial leading to pneumonia can come from secretions from the throat of patients intubated with endotracheal tubes (ET tubes) for long periods of time. ET tubes are inserted into the mouth and down the throat past the glottis, and because of this cause a great deal of inflammation and generation of secretions from the tissues surrounding the tube. The discomfort that results from the location of the ET tube in the throat and the inflammation caused by the ET tube means that most patients are kept sedated while an ET tube is inserted.
In contrast to the practice of medicine using ET tubes, patients may be awake after the installation of a tracheostomy tube (trach tube). The trach tube, more importantly, is inserted through an opening or stoma in the front of the throat of the patient, bypassing the glottis and other internal obstacles above the throat. This is critically important since bypassing these organs does not inflame them nor does it provoke the release of secretions in large amounts.
As a result of the advance in understanding of the role of ET tubes in possibly promoting VAP and the prophylactic effect of trach tubes, medical practitioners are moving patients from ET tubes to trach tubes at earlier and earlier times during their hospitalization.
This heightened awareness of the role of intubation in the onset of VAP has caused increased scrutiny of the design of trach tubes as well, since although the amount of secretions is lower with trach tubes than with ET tubes, it is not nonexistent. Conventional tracheostomy tubes typically have a curved tube that serves as an artificial passage for the exchange of air between a patient and an air source, typically either atmospheric air or a mechanical respirator or ventilator. The distal end of the tube is usually equipped with a small, inflatable balloon, also called a cuff, which can be filled with a fluid (e.g., air). The balloon adheres to the internal lining of the trachea in its generally cross-sectional dimension in order to prevent air insufflated by the respirator into a patient from escaping to the environment through the tracheostomy or the larynx and pharynx. This enables the air to reach the lower airways and eventually the pulmonary alveoli. The balloon also aids in supporting the tube inside the trachea.
Conventional trach tubes, unfortunately, are generally not well anchored within the body, as shown in FIG. 1. As a result, the tube can move a great deal inside the airway, as well as through the tracheal stoma and the wound. This instability and lack of anchorage can lead to a number of problems. Another issue caused by the poor anchoring of trach tubes in the trachea is that they may be accidentally dislocated, sometimes coming out of the airway completely. The reintroduction of the tube can be very difficult, since the stoma may be inflamed or damaged by the removal of the original tube. Additionally, even under normal installation conditions, the distal tip of the trach tube can cause damage and inflammation to the posterior wall of the trachea if it rubs against the tracheal wall as the patient moves, coughs, etc.
Other suggestions for controlling the movement of trach tubes with balloons that expand to hold the tube have been proposed. An example of such a balloon is shown in U.S. Pat. No. 6,612,305 illustrated in FIG. 2. While these tracheostomy tube devices may provide suitable control over the movement of the tube, the balloons appear to seal the tracheal stoma, thus limiting access to that region. Sealing the tracheal stoma inhibits the removal of secretions through the stoma and can result in the same problems as ET tubes vis a vis VAP.
A trach tube design that is more stable within the trachea than currently available tubes is desirable. A trach tube that allows secretions to be removed through the stoma in order to avoid the accumulation of secretions above the balloon, potentially causing VAP, would be an improvement over both the ET tube and currently available trach tubes.